Drakko

You'd also be wise to check into local laws on being a small ISP like this as this also opens you up to legal issues, say one of the users does illegal activities over this connection... I'm sure it varies by country or state to state depending where you are on "how much on the hook you are".

Other factor for the PC getting the slow/weird speeds is your cable from PC to router. If this is a stationary PC it would be less likely as the cable doesn't move so I doubt it would be so random but if you ever move the tower or its a laptop then a bent cable or stressed connector may cause some weird nonsense like this. If you have a spare I would replace it as a "just in case" anyways.

My guess is your PC or the port you're connected to on it is set at 100M/Full Duplex and not 1000M/Full duplex.

Is your setup a cable modem and then a router, a dual modem/router combo or a different setup with how you current access the Internet?

So for starters you can see your latency jumps dramatically on hop 2. Most ISPs now a days do something called ICMP throttling which makes traceroutes like this, usually unreliable for testing your latency (lag) however with yours it is showing a pretty consistently high value so more than likely there is an issue. I've never worked with your ISP before but they should have a customer support number or online chat feature you can use to open a trouble ticket with them and just give them the details of what you're experiencing, you'll also probably need your account number with them so try to find a bill either email or paper bill before calling. More than likely they'll run you through the basics of power cycling your modem and router and retesting through each step but if the issue continues past their initial steps they will escalate their ticket to their next tier tech to look into it further. Worst case scenario they find out they have to schedule a technician to come out to your house and check the cabling outside your house which may make it take longer.

I would imagine those CPU's aren't good for more than 4-5 players at a time for TPS or am I mistaken? Not sure of any differences between Windows VS Linux for that either. Those have 4x1gb NIC onboard so you could launch a VM on it and run pfSense to learn more about firewalls/routers.